261679431 has 24 divisors (see below), whose sum is σ = 381553536. Its totient is φ = 159438240.

The previous prime is 261679417. The next prime is 261679459. The reversal of 261679431 is 134976162.

It is not a de Polignac number, because 261679431 - 2¹⁴ = 261663047 is a prime.

It is a super-2 number, since 2×261679431² = 136952249216967522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 261679431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261675431) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49716 + ... + 54726.

It is an arithmetic number, because the mean of its divisors is an integer number (15898064).

Almost surely, 2^261679431 is an apocalyptic number.

261679431 is a deficient number, since it is larger than the sum of its proper divisors (119874105).

261679431 is a wasteful number, since it uses less digits than its factorization.

261679431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5143 (or 5130 counting only the distinct ones).

The product of its digits is 54432, while the sum is 39.

The square root of 261679431 is about 16176.5086158911. The cubic root of 261679431 is about 639.6217092241.

The spelling of 261679431 in words is "two hundred sixty-one million, six hundred seventy-nine thousand, four hundred thirty-one".